Heat exchanger



May 8, 1928. 1,669,291 D. K. DEAN HEAT EXCHANGER Filed March a. 1926 Call! FLl/ID I FIGURE 1.

Patented May 8, 1928.

UNITED STATES PATENT OFFICE,

DION K. DEAN, OF RAHWAY, NEW JERSEY, ASSIGNOR TO FOSTER WHEELER CO3- PORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

HEAT EXCHANGER.

Application filed March 8, 1926. Serial No. 93,201.

The object of this invention is an improvement in tubular heat exchangers.

In the heating and cooling of certain products, having scaling or corrosive properties, it is desirable to have the tube bundle or heat transmitting surface removable so as to permit substitution of a perfect bundle without undue interruption of service in case the tube bundle in operation in a heat exchanger becomes ino erative for any reason.

This requlrement leads to some difliculties in construction since in order to make the tube bundle removable, it is necessary to providea loose or floating tube sheet with its accompanying liquid chamber entirely within the enclosing shell of the heat exchanger. The fact that there must be a flanging space around the periphery of the space allotted for the insertion of the tubes into the floating tube sheet, to .provlde for the attachment of the li uid chamber, necessarily makes an unduly ar'ge space between the outside of the tube bundle and the containing shell. This permits the, short circuiting of a large amount of the fluid fiowing outside of ,the tubes, without being brought into proper contact with the heat transmitting surface.

The object of my invention is to provide means of avoiding this difliculty. In order to explain my invention more clearl reference is made to Figures 1, 2, an 3 in which like references apply to like parts in all figures.

Figure'l shows a cross-section of the complete apparatus which is a tubular heat exchanger. A shell 1 is provided at one end with a head 2 andwith fluid inlet connection 3 and fluid outlet connection attachment oftubes 6 and 7.

ends of tubes 6 and 7 op osite to sta- .tionary tube sheet 5 is provi ed a floating trance and exitof the 4. A stationary "tube, sheet 5 is removably attached to shell 1 at the end opposite to head 2 and furnishes means for At the tube sheet 8 to which is attached bonnet f9, which forms reversing chamber '10 6 mto tu es 7. A head 11 with inlet 12 and outlet 13 rovides for the enuid flowin through tubes 6 and 7. Partition 14 prevents the short circuiting of the fluid enterin inlet 12 directly across head 11 an idin the flow of fluid leaving tubes in Figure 1.

As shown in Figure 3, inner shell 24 exchanger in a direction countercurrent to the flow of the heating fluid. The cooling fluid passing through inlet the space 18 surrounding tubes 6 within shell 1. countercurrent to the flow of'the heatin fluid and to prevent the short circuiting o the cooling fluid directl across the spaces 18--and 1%) inside 0 shell 1 directly to outlet 4, longitudinal partition 20 ex vtending completely across the inside of shell 1 is provided. The cooling fluid therefore 3 "would enter.

In order that its flow shall be would be directed through space 18 outside of tubes 7 toward the floating tube sheet 8, would be reversed in flow in space 21 within outer head 2 and would flow throu h space 19 outside of tubes 6 and out 0 outlet connection 4. Bafiles 22 may be provided for bringing the cooling fluid more intimately into contact with tubes (46 d 647 Because the floating tube sheet 8 is lar er in diameter than the bundle of tubes 6 and 7 there is a space 23 of appreciable dimensions between the tubes and 7 and the inside of shell 1; In-order to prevent the short circuiting of the cooling fluid through the space 23 without comin properly into contact with tubes 6 and 7 inner shell 24 is provided. Inner shell 24 fits snugly, around the bundle of tubes 6 and 7 and while it ma be made up in any manner, a preferable cm is shown in Figu e .3, which shows a transverse section of the heat exchanger taken at 3--3 is made up in semicylindrical sections bolted to longitudinal partition plate 20 and may be removable if desired. A ring ber of passes 25 having some means for mahng close contact with the inside of shell 1 is provided to prevent the flow of the cooling fluid between the inner shell 24 and the inside of shell 1 through s ace 23.

Preferably this W0 (1 be attached rigidly to the'inner shell 24 as a flange with a ring of soft packing 26 set'in its periphery as shown on a large scale in Figure 2, although I claim as my invention any means for preventing the flow of fluid through space 23 In order to provide the same pressure within and without inner shell 24 a weep hole 27 is provided to permit the space 23 to fill with the fluid circulating in spaces 18 and 19 It will be apparent that while the space 23 will thus be filled and the fluid within it will thus be at virtually the same pressure as the fluid within spaces 18 and l9 no flow of liquid will take place within this space 23 after it is filled.

In this manner I shall with my invention prevent the by-passing of the fluidoutside the tubes around the heat transmitting surface without being properly brought into contact with such heat transmitting surface.

While I have shown a tubular heat exchanger arranged for two passes of both the heating and the cooling fluids with :1 Ion 'tudinal baifle and numerous ba es, I do not wish to confine myself to this particular type of tubular heat exchanger, but desire to make use of any numfor both the heating and the cooling fluid and any number or arrangement of cross baflies in combination with a floating tube sheet. I also retainthe privilege of circulating the heating or the coohng fluid inside or outside of the tubes, either in cross a concurrent or counter-current manner or in any manner whatsoever.

Having thus described my invention, I claim and desire to secure by Letters Patent- 1. In a tubular heat exchanger, a 'removable tube bundle, an outer shell, an inner shell closely confining the tube bundle and means for. preventing flow of fluid between the inner shelland the outer shell.

2. In a tubular heat exchanger, a removable tube bundle, an outer shell, an inner shell closely confinin the tube bundle, means for preventing. flow of fluid between the inner shell and the outer shell and means for maintaining substantially the same fluid pressure within the space between the inner shell and the outer shell as within the inner shell outside the tubes.

3, In a tubular heat exchanger, a. removable tube bundle, an outer shell, a floating tube "sheet, an inner shell smaller in diameter than the floating tube sheet and means for preventing the flow of fluid between the inner shell and the outer shell.

i. In a tubular heat exchanger, a removable tube bundle, an outer shell,.a floating tube sheet, an inner shell smaller in diameter than the floating tube sheet, means for preventing the flow of fluid between the inner shell and the outer shell, and means for maintaining substantially the same fluid pressure within the space between the inner shell and the outershellas'within the inner shell outside the tube.

Signed at Rahway in the county of Union and State" of New Jersey this sixth day of March, A. D. 1926.

DION K. DEAN. 

